[Progress in the study of potassium channels in cardiomyocytes]

The application of molecular biology and the development of patch clamp techniques led to a dramatic progress in the study of diversified and complicated K+ channels in the cardiomyocytes. Molecular studies suggested that all K+ channels are composed of four subunits encoded by genes from a big K+ channel gene family. The mechanisms of K+ channel inactivation include N-, C- and P-types of inactivation. S5-S6 linker was postulated to form the pore of K+ channels by site-directed mutagenesis. Though the molecular structures among K+ channels are very close, a wide range of their functional properties has been observed. The channel conductances, the characterizations of activation, inactivation, rectification and external K+ sensitivity, the agonists, antagonists and modulators of eight K+ channels found in cardiomyocytes up to now are different with each other.